SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd11c7493166dc00d85abe2e8093378ace074015bdd91635c42610c802b320803' 
  AND token = 'AfKX+MSKoMmH4fOb2BC210SDFxagV4AdAift7xKfFfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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