SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71672a89587381332cff306148be1ff703958ebd8fbba0a918c5fb5a7744de54' 
  AND token = 'yYquZvPeziOOjzDIJRDd1I/0ohIB3O/zIFiHtGK8cTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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