SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e46b593451ce482892d6dbf392356dcd241afcc44af3b629afa26a11e7d1bc79' 
  AND token = '0Ok282DVXfhJL/GmBgTGGjvhdTaOr9akTnu1PPCZX8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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