SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb294960959c7ae9ca41bba058660742ed4afdef2871548d4bda8086ee9f8f3' 
  AND token = '2fFOyTNdW66Ukd1VNVvvwBFKuzc1opWfaGYNo3tfsXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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