SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d8cc734cfbb6bc8c43e585df720e5192f74309d4873cbe47296bf7d56c98a69' 
  AND token = 'RCth0hSOyTFYBDLPP/eCBgI0PZpML1/b5BV29t/Zg+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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