SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8de2f85ad31e8494c58b861d14de751540962847993db216bcc848b88d0ec03' 
  AND token = 'gDGUqm/7OqbiyWH4FYzCUMyb7AIDySWKPAgTZiKYn6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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