SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5342d83fedafd4d950853090ce64f11a935cc6bb81743f3481c08179b7b1235' 
  AND token = 'z3gOL9MD7IscilnjqfLpbYqjEu2kLZpuwhHCTYsZMQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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