SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4099aa7419af64002ad29f5bd075c87345643e9a2a1505be186360f28db879f2' 
  AND token = 'GyMZqYgLiyRyJC0BniwwBWn7boc5ZhUXq3PcNySNhX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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