SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c84033d7675bdd0270a703ce34151ded23d04bae2181502c4e424a51a9e9733' 
  AND token = 'MTGcOsdlCX665BgCb6paYugMQI1lIgJkdpjpp/7ZnVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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