SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8324af28910eefce3ca44daca160e527cbe295e918c8f83c3df1d56b1fabc7fb' 
  AND token = '74H6dbol1xBkASCQD4IGX6IjWMY1tgfUXQSfrU2psZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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