SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '74dad8765bc00b8fe8cef187e85d238828a33a24d79fbdce49c2dad9b6ab705a' 
  AND token = '8Cll6mYusuqWy85FrFoDQu+sF5a7rXtKSifgWAAW3xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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