SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '483b78137c79c8ce6ad8e9d7aa442b3569b3a89d1a96251b5eedcbf470c6673c' 
  AND token = 'xBZgMprXkw0N1uyfFI4FO3pRzViC1K/0LKVwMkMRYOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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