SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd71b4321731d47325dbf1da700108558d06c0ab8e38f82e96349035b8cee7bf' 
  AND token = 'rnpdZbIKBbDEpTeRRSZcJ+V7o8CaGO4Tz4bB8YGAIMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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