SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5104068c408f488f0caf56946738cde7af00b241cc98e60b7db52f821d5fddef' 
  AND token = 'VJFPeKXZzcWXm/83KSmAxN6j9hXVBBfTT+wjGjUjMEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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