SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f414e16cf922b0b3dbabc80b2cb81547a9cfbd4eb2f8576ae934945a2401c9c2' 
  AND token = 'hJqyXyTw2DwYoF11N7BCzA9yAMENCGpzqnd7ebmzAv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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