SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a1691b8582acd9a0b4fa6d397c054e2f38e19ba317811b77866ac5c7a5a5967' 
  AND token = 'PZI13AFOKx+7Zvr40o+iUCLh8RuVEg4GPjKBZIylPLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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