SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb05a0c257b3fb29ff47e7ac75bd609927a9a89a4ae85a21fc3002e669ad8888' 
  AND token = 'KEXH352wfgbKb2jMQWxU/O76o/lqUkymptSUzrMoSoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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