SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa089510181b39dc3a39476951c284a11bb82a141eac6ee1b3fe408d6e7a3836' 
  AND token = 'lnx0QdVGmLOi4k4pj4NaZGWLy4b9aEv5Kop2uKdTjU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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