SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3edf4bbd5a64d571fb15e529e49b51d97b5f87df8f3122610dd60fc6f5491587' 
  AND token = 'eK6naHuKg56RNQHqRvA5U6RdQeHwSHvp0V3EmjbWqEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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