SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '357fe8a85ac7ed0b68efe0b199dfa067d532740b340a158d90e553496a88989f' 
  AND token = 'hA/2/+XEJT32GNm4WwuTQ9975zQ2teyzySqsdMhjEuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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