SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b28aa9dface08d4b8e09ff7846cfd5fcbff7fcc8ad1bceaec8288cf5e6615eb' 
  AND token = 'tnspRTY3KgGAzDhOb1f2/9UltZJOI5hWgB8j7PwcGSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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