SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bf9b03d540b367de70f31e4a26d18da9825e483470ce467edd8f7086d770ea1' 
  AND token = 'cldPLMz7ic8BMkU0+sYfpul5eHBgTqrNbQnj6qonSoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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