SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68fb8ea2989fb1f7c173e7bf1067cfbb0fd397602ab280b594d65c96f9be4c70' 
  AND token = 'AB0k1MmKx5Xdqy6vhPPG/9CujQhFeXfVehgF4Hdx+XA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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