SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a18848b02cd5c5ef241d0ee046b774d59434eb8cbd21ee6f7422872c09806281' 
  AND token = 'LaLnXAYQnl0364i55MnK7ZUIy9qDIDlIQOReHQ0S0Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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