SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd050b5ddc0d844db378b950014fc3780384efbec52ad81831e3e477e7d9282d' 
  AND token = 'j/66SM/Mu9YC/1kTbUAXd8VhRxaHTtW+9NZfH9LZTkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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