SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f27dcdfa375602d950977325baa1ffbd753e058f0ec00081e3b9246b4ff9ba0' 
  AND token = 'RWT9P5ZmqTK47PEX9vvM+PhsGBjcK2yeGzq2RwrfX68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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