SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4394e4ee3ede706aa91a0723ee461810e6f77b2f04adec245d57729771fe9c9' 
  AND token = 'AwbNOOJi4NXsUeJPdKW9fE68N3M6xQDHiWy/vXkE0N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}