SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69df7ed27b245c5986a84f6344734b8be6f9ab65717880d07971cbe79bd82ff1' 
  AND token = '3uyQw3pWwhEoO1WOXKjv4boHMGq5vhUbcvjUU7qjCoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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