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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6af79d261c87207d6a98c0f595ca53cbc68ac2b44ee12f6edfcf2a2ce44454f' 
  AND token = 'J+WA4yzSn7DAx8QCuclwTRwf9mB+4tiQfoVKIZu5vlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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