SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bdf72660b0c7dc88858becf4d063969b1fd0dccd2a70e480128025d820adc8cc' 
  AND token = 't3ZvoMZFXbAAmPOe/HZoE3pSS+sTy1S7qL4rLwqzy4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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