SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e35c61319e391f36ddfcd515a37d3eafb37a53ecc8e00c8353d16c5ed8698067' 
  AND token = 'E0cQqmSiSusB+adu9ttpUV9hFCBtS9rmMb8IdqzIveo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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