SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f5ecadb3b6fd6fe787a3967da5a21a40613b6c7db842b8280533b719318be24' 
  AND token = 'mE7JCPQ/BR2xB9uM4wB0Wy7yAjGO+HmjXznxcne1Bvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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