SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '349b41fa37e2982b66676a0af091084bc3c588b12903a4b8189cd17e19821092' 
  AND token = 'zV+O49KKoY5KM8+QfFIahUYxxZSXP/WcjQSh24Y7s3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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