SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c2d21a926a440e8e10e930ba3e38a284f0d6c2bb6a8c6d7e32a4b0ca204af1e2' 
  AND token = 'siMp8u3q5pQBaTvUtu/rfnZOi6PwZVNXvgs+gf6lxxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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