SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5067d1e70005f09b743c3d88098fd0421d2c3b4d045fb1bbe08463d84a8bddab' 
  AND token = 'jMu512YIAlE3pdk1sAkegjXAjVuB8fd4t4U3W2lYI5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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