SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59872734f0f40f595b87ece23a57df486ea8bfe82f10f3943435770d06a8c1d0' 
  AND token = 'G5WJvJ9zJdlVLtQBEwST8PwiVL9cYvAhWhfPjTg+g7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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