SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4114a79169698b17747aa7ce110afdec01511b85e685b8f8a9937352c3436936' 
  AND token = 'lCHJSAz5JvkwsNptn3RbkOnpSptGz/n4uTNBoWPf2m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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