SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5f373788dcdcbbdf0903b33726a38b34dea09871069614a22c858f676bf938' 
  AND token = 'RPpmpH0joCVP2VQWzi7Cy74p6mEWu/SAjpdkhWYr7Qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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