SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd4d8cc31c7849b19cd2e415d4fa581dd86ee2ffe2c694064ca2f2fdb0c2028' 
  AND token = 'yDklWyNUfvgd4yWoUp2cGo8BBe+BKQ0EPZW1iimBNHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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