SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1417390d3ca92b05c7a27990669c4b412f81d4039e20aacd9fd3ccd4594ea41a' 
  AND token = '6IfgMTBey+ZolQqDGLzFz/8kJ9AQwInyR/Qn+VsAum0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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