SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4874a0b6433534b691bd8f7dc02935381cce3617665b65a9bb1441e4c5714121' 
  AND token = '6RPZzQfQUOMbevhKz7VXyu/0jJHQxU4A+Da2gNn1/iE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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