SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b9897f489a5ce780e0519d5b34d3f7c7f153653c6e225da912747899b796a2' 
  AND token = '36Lg4xefgCFa/njqezt4ZwldtpfQo6BoMCsRvXgfgWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00081

JSON explain

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