SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a3b404763627296fbdd467b543822eec95e39d7f19823ecdf219b4acabc3be2' 
  AND token = '581Z1PlO61ryLTO6nFVv1n1pd6uTVpxzco6dAK7cA6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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