SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a500f3923575dce723721daadb9c74f2eb83d290e64722e152a0ab430cf338e' 
  AND token = '8DPYIYaEIeY2id82S63rIW0UNJSVZejHPdjYpy89ydE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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