SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c44ce8ccf4b47421f83edd1506ee261bbfac4c8bbc3a63b063387cc5318117c' 
  AND token = 'ZB68ntuH8kFMJRdcqqAZ+QY9TjcpaDujjILUgxke0os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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