SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d0d582fd0f60a2afba4591a34314169ab95432caef3b67b954844d2673d8652' 
  AND token = 'B8XnX4qjKL/nBHxOKb3OMpnwvO32Ugvy4tijZJN5EgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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