SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21e89bf585458d9580a3d5d7b1df24fce253669ffd8f3a2dcf2077e98025eb16' 
  AND token = 'rWDw2zKzJ/ev5Zc+MXqNSnO4+gVCaEMIPouqqlm09jA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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