SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5472bd63bd34c246a5c36e08f0c8e7488e4c318a4923183a775e2cc66f1b8b7' 
  AND token = 'vvDzX3Z1m7/C/cvR5Q6eJuDg+76FXs49zLLuFxHpXcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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