SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e84faf0657db0bf47edfb11f3b05a8c489637295316338f6868e1aa09797056c' 
  AND token = 'mAcyV67Rjxm02t79ST2jjwf9zqCGxqFcXzJKhGP3tJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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