SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '640bb0798cf4406a853c3c643af28d0d5333b900278377eb04a54cca0988f5b3' 
  AND token = 'cApIFPQNOyyLlYEBNqzeFpPQWrCoR45KyCW1yXvZKEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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