SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f28cbcc6287739a78969866f5ca41235784124790103218d7f301c1687a9e14d' 
  AND token = '3r7pbFliPesG03yG2IO7sNzuRT/2Mof+lT+pDMckJd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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