SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30c64cd185cce0ce593370a326f151b0cecdbcac7a61c97310585f28ffd0149' 
  AND token = 'j91RW1gYFHsZVVtXv6MDD9v/CtGNVR3Tcdd0gk+99vM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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