SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd35197e760c0139f7ccb6707aa3986893a8afa0cf3617e4699fa2fc80956703d' 
  AND token = 'oVw4zkrnLGDEjG0GeAGPG+paZQCVOul/GQkhUzVL7PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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