SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '991b24e4901d6fd880ddfa4708dad4c488328295b14765210e12c08fbfb751f4' 
  AND token = 'LOrKI98IRE71+7djxw9GqBLB9YCWCJbNraRqu+YvZgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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