SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '188f2c63f843b5e94ef93d9b6dc027c874cadcbdcaa2bb0d8f8cff82ee5747e9' 
  AND token = 'z/4fpWq+6j7gQMpHpe7q4gkLJeDD2GSGwLrIrl0YFjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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