SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba1c8de24a8fc1d5864be439001b6dd58a2b8b546dfbaf9965ad7ed56f3d54d6' 
  AND token = 'fPvNghP8TF0jEhnmhbI4jR7mWIIqmifZwaViJ+TYKYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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