SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1896abf192627ae972b82ee38b2ae247cd1d8ad795849456a2140115cd9ec7c1' 
  AND token = 'JLgAD0ZWmOLliU7CLBLgeVLB+/SJdKw/zUASnxvO1u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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