SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b3bc2a6752410dca5b67d42792e1b285888cb8afdb6dc9d74c12fa496fbf9d5' 
  AND token = 'ZY844muFqoa+HU77OCnHYiUM+qoC57S/Fb4bFNeVnl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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