SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f2560293062496e784477a316cd9029e146ebf7e6cdd36df58e94b9b1dea714' 
  AND token = 'irNV7zTttH+U34L5NY/kFtuJMnSw9PtBCSKjYPUtSHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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