SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466c6bd8bf15bce4ec93a8a8707b07a02251d2bd2c23dc604fc167f249e74257' 
  AND token = '4qkhkE6qtHGUfXWrlHvfLrwncwqzBQfpe/I12ZyeBbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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