SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9736f2ba541b8fc55b7f98c5a49aa7245c75bf55623c7e7ddae9d747a237e4ba' 
  AND token = 'EQ2sjpgIzsVo5SLu6dWpcgJXHnRh26+xG1KYeAk4TJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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