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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e9d66107e774de33b03f684df5d47a482f9c299cf3ab81c56e099cbcc4cc52' 
  AND token = '/htMmTZ3PGDFwz5635F4vcpZiga4rkL+a99itjnD4vM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}