SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f37402021180cd140508ebb92854f24094f594b99c5df466df741872dbf084e5' 
  AND token = 'FsISgIZV6VvBTtpQ1LwotdbPW53FXJtwsa8zBxc3DXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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