SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3a95e6823ab0e197c9218d87736e32942df1167a01c379e807362ad343c4e8e' 
  AND token = 'BL0GgsVliTrKQmjkldHBOzqNR/YWK3MeWaZpcxDrGhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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