SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dbf66c3bb09c9b5ae89197d754be97cdb01220a8c5d0939b9a0d8264bbe02b2' 
  AND token = 'gGca6lUp7mnRzgrAXqxVOlyMR/PLoJcNLlYkkoMvOvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}