SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94d0bfde0bf7e532d2b4c3884ac141ed4981f8aab043d706a732709dd996aaf1' 
  AND token = 'FosOMOHkp+hwaK7EcIgx+yc7HM7QMs52XGNizgaWKFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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